Air cooling system for internal combustion engines



c. T. DOMAN 2,142,499 AIR COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Jan. 3, 1939.

Filed April 20, 1957 2 Sheets-Sheet 1 ATTORNEYS.

C. T. DOMAN Jan. 3, 1939.

AIR COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed April 20, 1937 2 Sheets-Sheet 2 E IINVENTORN VATTORNEYS.

I .IIIQIIIIII a i vwv HUM Y (Ii/ B IIJ........... 2 WKrFFFFrE/EM'FE X /%.I EzzsiZiU/ Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE AIR COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES New York Application April 20,

7 Claims.

This invention relates to air cooled internal combustion engines, particularly engines which are cooled by a blast of air coming in from one side of the bank of cylinders and passing over the heads of the cylinders and between the cylinders, and has for its object, means for cooling certain dead spots or dead fins on the lee side of the engine, with respect to the air blast or portions or fins not encountered or wiped by the main air blast, particularly portions adjacent the valves in the heads, which are shielded from the main air current by obstructions, such as the parts of heads in which the valve ports and the guides for the valve stems are formed.

Other more specific objects will appear throughout the specification.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a plan view of this air cooling system, the bank of cylinders being shown diagrammatically, the heads of some of the cylinders being removed.

Figure 2 is a transverse sectional view, parts being omitted, taken approximately on line 2-2.

Figure 3 is a fragmentary plan View, similar to Figure 1, of a slightly different form of the invention than that shown in Figure l.

The air cooling system of the invention is shown as applied to the type of engine shown in patent of Carl T. Doman, No. 2,043,531 issued June 9, 1936. In this type of engine, there is one valve, preferably the exhaust valve, in the head of the engine. Both valves may be in the head, as shown in the Doman Patent No. 2,052,017 issued August 25, 1936, or both disposed as in an L head type of engine.

The barrels of the cylinders and the heads are formed with heat radiating fins and the cooling current from the main conduit is projected against one side of the bank of cylinders and passes between and around the cylinders and over the heads thereof to the other side of the bank. With the cylinders spaced apart, the transverse air currents are sufficient to also cool the lee side of the barrels of the bank of cylinders with or without deflectors, but certain 5 portions of the cylinders are heads, as those adjacent the intake and exhaust ports, which are shielded by said ports and the portions of the heads in which the guides for the valve stems are located, are not cooled or encountered a by the transverse currents.

1937, Serial No. 138,004

On the lee side of the barrels of the cylinders, there are usually parts that incidentally act as deflectors to deflect the transverse air currents around the lee sides of the barrels of the cylinders. These parts may be the tubes enclosing the lift rods for the valves. However, there is nothing inherent in the engine itself to deflect the transverse 'air currents against the portions of the heads and barrels which are shielded by the ports and the portions of the heads forming the guides for the valve stems. The fins on these portions are referred to in shop parlance as dead fins.

This air cooling system comprises an air conduit extending along the opposite side of the bank of cylinders to that on which the main air conduit is located and arranged to discharge against the dead fins, this conduit, particularly in a long engine, as an eight cylinder engine, being connected to a source of air at its opposite ends so that air is discharged against some of cylinders, as half of the total number by fresh air from one end of the conduit and the other half of the total number of cylinders receive an air current entering the other end of the conduit.

1 designates a bank of cylinders, these being suitably mounted on a base 2 and spaced apart to provide transverse air passages 3 between them and around the cylinders. The barrels of the cylinders are provided with heat radiating fins 4, and the heads 5 are also provided with fins, particularly on an upwardly projecting portion 6, which is provided with guide passages for the stems 1' of the overhead valves 8 and with the ports 9 for the valve.

The engine here shown is provided with one overhead valve, as in Patent No. 2,043,531 referred to, this being the exhaust valve, and with an intake valve l0 extending through the intake port II and with its stem extending through a guide l2 formed in said port. The intake and exhaust manifold are connected to the ports H and 9 respectively.

The overhead valve mechanism, which forms no part of this invention, is mounted on a suitable support, which in turn is mounted at l3 on the top of the projection 6. The head 5 is provided with fins l4 between the ports 9 and l I. These ports and also the projection 6 shield the fins from the transverse air currents. Hence, these shielded portions of the heads become hotter than the remaining portions of the heads and distort, causing the heads to distort and upset the alinement of the valves and valve seats and also develop leaks between the heads and the barrels of the cylinders. Also, the valves, which are the exhaust valves in this engine, are not adequately cooled.

The feature of this invention is the adequate cooling of the dead parts of the cylinders or the heads thereof.

I designates a main air conduit extending lengthwise of one side of the bank of cylinders and being open at one side toward the cylinders to discharge air against the bank of cylinders and through the transverse passage 3 between the cylinders. The conduit I5 is here shown as extending the full height of the barrels of the cylinders and. their heads.

I6 .designates a second conduit extending lengthwise on the opposite side of the bank of cylinders to that on which the conduit I5 is located, this being located to discharge air only on the dead portions of the cylinders, that is, the dead fins I4. This conduit is of such height as to discharge only on the dead fins and to extend between the intake and exhaust ports II and 9.

The means for creating currents of air through the conduits l5 and I6 may be of any suitable construction, as a fan or blower, including a housing I I in which is located a fan I8. The fan is usually located on the crank shaft of the engine. The conduits I5 and I6 communicate at their front ends with the discharge side of the fan housing, at I9 and 20 respectively. The conduit I6 also communicates at 2| with the rear end of the conduit I5.

Thus, the air through the second conduit I6 passes thereinto in opposite directions, and preferably a partition 22 is provided in the conduit I6 located midway of the bank of cylinders, so that substantially one-half of the conduit I6 discharges air on one-half of the bank of cylinders and the other half of the conduit on the other half of the bank of cylinders. In order to avoid excessive back pressure, the conduit I6 is also provided with additional outlets at 23 adjacent the partition 22. These outlets assure free passage of the air currents through the conduit I6 and also through the main conduit I5, owing to the fact that the conduit I6 is connected to the rear of the conduit I5.

Air splitters or distributors 24 may be provided in the conduit I6. In the engine here illustrated, the air splitters are arranged so that each two cylinders of a straight eight cylinder engine receive fresh air currents, that have not been encountered by any other cylinders or heated parts.

55 Also, as seen in Figure 4, additional outlets 26,

similar to the outlets 23, may be provided at the end of each deflector or splitter 24.

Owing to the air conduit I6, the dead fins on the lee side of the cylinders, with respect to the air blast from the main conduit, are adequately cooled, and uniformly cooled with respect to the remaining parts of the cylinders cooled by the main blast of air from the main conduit I5, particularly the dead portions adjacent the exhaust valves, which are shielded by the valve guides and ports.

What is claimed is:

1. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, of an air cooling system comprising an air conduit extending along one side of the bank of cylinders and open at one side toward the cylinders, whereby the air passing through the conduit is projected against the side of the bank of cylinders and transversely between the cylinders, a second air conduit extending along the opposite side of the bank of cylinders and open throughout its length toward certain portions of the cylinders not encountered by the transverse air currents, and means for creating air currents in one direction in the first conduit and in opposite directions through the second conduit.

2. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, of an air cooling system comprising a main air conduit extending along one side of the cylinders and open at one side toward the cylinders, whereby the air passing through the conduit is projected against one side of the bank of cylinders and between the cylinders, the air conduit extending substantially the full height of the cylinders to project the air against the barrels and the heads of the cylinders, a second air conduit extending lengthwise of the opposite side of the bank of cylinders and open at one side toward the cylinders, the second air conduit extending along the outer end portions of the barrels and along the heads and arranged to direct air currents against portions of the cylinders and heads not encountered by the transverse air currents from the air conduit, and means for creating air currents through the main conduit in one direction and through the second conduit from opposite ends thereof.

3. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, of an air cooling system comprising an air conduit extending along one side of the bank of cylinders and open at one side toward the cylinders, whereby the air passing through the conduit is projected against the side of the bank of cylinders and transversely between the cylinders, a second air conduit extending along the opposite side of the bank of cylinders and open throughout its length toward certain portions of the cylinders not encountered by the transverse air currents, and means for creating air currents in one direction in the first conduit and in opposite directions through the second conduit, the second conduit having a partition between the ends thereof.

4. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, of an air cooling system comprising an air conduit extending along one side of the bank of cylinders and open at one side toward the cylinders, whereby the air passing through the conduit is projected against the side of the bank of cylinders and transversely between the cylinders, a second air conduit extending along the opposite side of the bank of cylinders and open throughout its length toward certain portions of the cylinders not encountered by the transverse air currents, and means for creating currents of air through said conduits, said means comprising a fan casing and a fan therein, the conduits being connected at like ends thereto, and the second conduit being also connected to the first conduit at a point remote from the fan casing.

5. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, of an air cooling system comprising a main air conduit extending along one side of the cylinders and open at one side toward the cylinders, the air conduit extending substantially the full height of the cylinders to project the air against and between the barrels and against and over the heads of the cylinders, a second air conduit extending lengthwise of the opposite side of the bank of cylinders and open at one side toward the cylinders, the second air conduit extending along the outer end portions of the barrels and along the heads and arranged to direct air currents against portions of the cylinders and heads not encountered by the transverse aid currents from the first air conduit, and means for creating air currents through the conduits including a fan housing and a fan therein, the main conduit being connected at one end to the fan housing, and the other conduit being connected at one end to the fan housing and at its other end to the first conduit at a point remote from the fan housing, whereby currents of air are created in the second conduit in opposite directions from opposite ends thereof.

6. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, the cylinders including barrels and detachable heads on the barrels, and at least one valve, valve guide and port in each head, of an air cooling system comprising an air conduit extending along one side of the bank of cylinders and open at one side toward the cylinders to project air passing through the conduit against one side of the bank of cylinders between the cylinders and over the heads, and a second conduit arranged on the other side of the engine and arranged to project air against the portions of the engine cylinders and heads adjacent said valves, which are shielded from the transverse currents by the guides and ports, means for creating air currents through the conduits, said means including a fan housing and a fan therein, each conduit being connected at one end to the fan housing, and the second conduit being also connected to the other end of the main conduit, whereby currents of air are projected through the second conduit in opposite directions from opposite ends thereof.

'7. In an air cooled internal combustion engine, the combination with a bank of spaced apart cylinders providing transverse air passages between the cylinders, the cylinders includin barrels and detachable heads on the barrels, and at least one valve, valve guide and port in each head, of an air cooling system comprising an air conduit extending along one side of the bank of cylinders and open at one side toward the cylinders substantially throughout the height of the cylinders and heads to project air passing through the conduit broadside against one side of the bank of cylinders between the cylinders and over the heads, and a second conduit arranged along the other side of the bank of cylinders and narrower in a vertical direction than the first conduit to project air against the poi-- tions of the engine cylinders and heads adjacent said valves, which are shielded from the transverse currents by the guides and ports, and

means for creating air currents through the con duits, said means including a fan housing and a fan therein, each conduit being connected at one end to the fan housing to receive air discharged therefrom.

CARL T. DOMAN. 

